I know that this group is usually great about posting highlights during the briefing, I was hoping this trend would continue as I'm blocked from watching anything by the network at my job. So please, keep a running thread about what's being said. Thanks in advance.

LOS ANGELES - A provocative new study of photographs taken from orbitsuggests that liquid water flowed on the surface of Mars as recently asseveral years ago, raising the possibility that the Red Planet couldharbour an environment favourable to life.

The crisp images taken by the Mars Global Surveyor do not directly showwater. Rather, they show apparently recent changes in surface featuresthat provide the strongest evidence yet that water even now sometimesflows on the dusty, frigid world. Water and a stable heat source areconsidered keys for life to emerge.

Until now, the question of liquid water has focused on ancient Mars, andon the Martian north pole, where water ice has been detected. Scientistshave long noted Martian features that appear to have been scoured bywater or look like shorelines, and have tried to prove that the RedPlanet had liquid water eons ago.

"This underscores the importance of searching for life on Mars, eitherpresent or past," said Bruce Jakosky, an astrobiologist at theUniversity of Colorado at Boulder, who had no role in the study. "It'sone more reason to think that life could be there.''

The new findings were published Wednesday in the journal Science andNASA scheduled a news conference for Wednesday afternoon to announce theresults.

Oded Aharonson, an assistant professor of planetary science at theCalifornia Institute of Technology, said that while the interpretationof recent water activity on Mars was "compelling," it's just onepossible explanation. Aharonson said further study is needed todetermine whether the deposit could have been left there by the flow ofdust rather than water.

The latest research emerged when the Global Surveyor spotted gullies andtrenches that scientists believed were geologically young and carved byfast-moving water coursing down cliffs and steep crater walls.

Scientists at the San Diego-based Malin Space Science Systems, whooperate a camera aboard the spacecraft, decided to retake photos ofthousands of gullies in search of evidence of recent water activity.

Two gullies that were originally photographed in 1999 and 2001 andre-imaged in 2004 and 2005 showed changes consistent with water flowingdown the crater walls, according to the study.

In both cases, scientists found bright, light-colored deposits in thegullies that weren't present in the original photos. They concluded thedeposits - possibly mud, salt or frost - were left there when waterrecently cascaded through the channels.

The Global Surveyor, managed by NASA's Jet Propulsion Laboratory,abruptly lost radio contact with Earth last month. Attempts to locatethe spacecraft, which has mapped Mars since 1996, have failed andscientists fear it is unusable.

NASA's durable Mars rovers have sent scientists strong evidence that theplanet once had liquid water at or near the surface, based onobservations of alterations in ancient rocks.

"We're now realizing Mars is more active than we previously thought andthat the mid-latitude section seems to be where all the action is," saidArizona State University scientist Phil Christensen, who was not part ofthe current research.

Mars formed more than 4.5 billion years ago and scientists generallybelieve it went through an early wet and warm era that ended after 1.5billion to 2.5 billion years, leaving the planet extremely dry and cold.

Water can't remain a liquid for long because of subzero surfacetemperatures and low atmospheric pressure that would turn water into iceor gas.

But some studies have pointed to the possibility of liquid water flowingbriefly on the surface through a possible underground water source thatperiodically shoots up like an aquifer.

Oh, I'm not so sure of that... (though the Daily Mail, the original "fascist rag", is hardly a journal of record.) Steve Squyres did say that Spirit and environs was pretty high up the priority target lists. Unlike the VC image, I imagine there'd be no need to rush-release the image. I'm rather hoping it's both... perhaps a gully has appeared on the side of Husband Hill

You probably thought he was American because his voice-generating computer was built by an American company -- so he has an American accent! He's also one of the few Brits who appears regularly on The Simpsons...

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted.
Do not reproduce without permission. Read
here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the
individual posters and do not necessarily reflect the opinions
of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer
UnmannedSpaceflight.com moderation team is wholly independent
of The Planetary Society. The Planetary Society has no influence
over decisions made by the UnmannedSpaceflight.com moderators.

SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society
and is funded by donations from visitors and members. Help keep
this forum up and running by contributing
here.